I am the first in the world

[Farsight]

Bare assertion, contradicted by evidence...

No, that page was given us by Misner, Thorne, and Wheeler circa 1973...

It may be new to you, but it isn't new to us. We did our homework years ago...

Bare assertion, contradicted by evidence...

Drone drone, you've got nothing. You can't tackle this argument, your facile exercises merely highlight your inability to address the issue, and you have no evidence. I'm the one presenting evidence here, not you. Evidence such as the Shapiro delay, and optical clocks losing synchronisation at different elevations:

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Care to challenge that and tell everybody that the two light beams above are moving at the same speed? No, you'll just make pompous assertions that fool nobody.

You must not understand what people mean when they say a spacetime is static.

I understand it. Spacetime combines space and time into a block-universe mathematical space. It's like filming a red ball, then cutting the film into individual frames and stacking them up. There's a red diagonal streak in the stack of frames, that's the worldline of the ball. The ball doesn't move through spacetime, nothing does. That's why it's static.

Simplifying somewhat for the present audience, a spacetime manifold as described by some particular chart is said to be static if the metric's coordinate-dependent components are independent of the chart's timelike coordinate. It's a property of the chart as much as the spacetime...

Simplifying even more, have a read of Nasty little truth about spacetime physics

"Some of the most famous physicists in the world are not telling the truth about one of the most taken for granted concepts in scientific history. They are not telling us how they can come up with their fanciful time travel theories (wormholes, advanced and retarded waves traveling in spacetime, etc...) using a model of the universe that precludes the possibility of motion. Nothing can move in spacetime or in a time dimension-axis by definition. This is because motion in time is self-referential..."

Next.

 

[sol invictus]

Oh spare me your schoolboy ignorance, RC. Go and look at Kruskal-Szekeres coordinates on wiki. You'll read things like:

The location of the event horizon (r = 2GM) in these coordinates is given by
[latex]V = \pm U[/latex]

Sheesh. You've linked to it, but you haven't read it.

All: you really should correct RC when he makes errors like this. When you don't, I'm afraid you damage your credibilty.

I don't read every post in this thread. When I do read something I disagree with, I usually comment. In this case, you're correct and RC is wrong. The existence of a black hole event horizon is a physical fact, and its existence doesn't depend on coordinate choice.

However: the existence of many other types of event horizons (Rindler, cosmological, de Sitter, Poincare, etc.) do depend on coordinate choice, and those horizons have exactly the same properties you are using to argue that the black hole horizon is a special place. Therefore, your arguments do not suffice.

 

[W.D.Clinger]

All: you really should correct RC when he makes errors like this. When you don't, I'm afraid you damage your credibilty.

Reality Check should have said there is no coordinate singularity at the event horizon in Kruskal-Szekeres coordinates. Adding those words in blue to his statements fixes them.

Vorpal corrected my remarks on static spacetime as described by some particular chart, and added that one can also give a coordinate-independent intrinsic definition (as in the second paragraph of Wald's section 6.1).

I appreciate Vorpal's corrections. I had forgotten about the cross-term issue. I was attempting to define the chart-dependent notion of static spacetime because (1) it's easier to explain and because (2) it's the notion Lemaître was using when he said the Schwarzschild coordinate singularity at r=2M "arises simply because one wanted to use coordinates for which the field is static".

The results of physical experiments are independent of coordinates, yes.

In particular, the fact that a mirror-clock keeps on ticking as it passes through the event horizon of a black hole is independent of coordinates. The fact that its continued ticking will never be observed by an observer at infinity is also independent of coordinates: an observer at infinity is outside the forward-directed light cone of any events that occur within the event horizon.

Farsight's mistake (well, one of many) is to misinterpret one particular observer's inability to observe the ticking as evidence that the ticking has stopped.

I have indeed capitulated, in the sense of complete resignation that you are too far gone into crank-land for any possibility of productive interaction. Many other posters here are not to that point, and that's their business.

For those of us who don't understand relativity so well as you and a number of others here, interacting with Farsight gives us a chance to test our own understanding of the subject. It has also motivated me to work through some calculations with Lemaître coordinates and to check Wald's very similar derivation of Kruskal-Szekeres coordinates.

Besides, we don't often get a chance to rattle the conceptual cage in which some soi-disant cage-fighter has locked himself.

 

[Farsight]

I'm just spelling out to you what your ideas, as stated, imply. If you feel you have been misrepresented then perhaps you need to examine how you communicate your ideas.

Or examine that misrepresentation.

You said (post #168 in this thread, and also during the old Relativity+ thread) that the effects of a black hole's gravity on an infalling object can be understood in terms of variations in the "vacuum impedance of space". You said it was "that simple". Those were your very words.

Yes, it is simple. Two parallel-mirror light clocks at different elevations don't stay synchronised:

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One light beam is going slower than the other, and c = √(1/ε₀μ₀). The vacuum impedance of space is Z₀ = √(μ₀/ε₀). It's only complicated when one asserts that c and Z₀ are the same at both locations.

I repeat: If your theory can be understood in terms of a scalar quantity (e.g. vacuum impedance) that varies from point to point in space, it absolutely cannot be equivalent to GR.

And I repeat, this isn't my theory, because Einstein said this:

1911: If we call the velocity of light at the origin of co-ordinates co, then the velocity of light c at a place with the gravitation potential Φ will be given by the relation c = co(1 + Φ/c²).
1912: On the other hand I am of the view that the principle of the constancy of the velocity of light can be maintained only insofar as one restricts oneself to spatio-temporal regions of constant gravitational potential.
1913: I arrived at the result that the velocity of light is not to be regarded as independent of the gravitational potential. Thus the principle of the constancy of the velocity of light is incompatible with the equivalence hypothesis.
1915: the writer of these lines is of the opinion that the theory of relativity is still in need of generalization, in the sense that the principle of the constancy of the velocity of light is to be abandoned.
1916: In the second place our result shows that, according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity and to which we have already frequently referred, cannot claim any unlimited validity. A curvature of rays of light can only take place when die Ausbreitungs-geschwindigkeit des Lichtes mit dem Orte variiert.

So, is it really "that simple"?

Yes.

I never claimed that we live in a homogeneous or isotropic space. Since you took the trouble to post this, though, you should note that he refers to ten functions g_μν, these being the components of the metric tensor for a four-dimensional spacetime (in 3D we'd have just six functions). GR's field equations are fundamentally four dimensional.

They describe the metric qualities of space. The way you measure distance and time, both via the motion of light. And it doesn't vary in a linear fashion, because the energy of a gravitational field shall act gravitatively like any other form of energy.

GR has inhomogenous, non-isotropic, curved 4D spacetime. Einstein just told you that, above, but you somehow missed it.

No, read what he said. Here it is again:

"According to this theory the metrical qualities of the continuum of space-time differ in the environment of different points of space-time, and are partly conditioned by the matter existing outside of the territory under consideration. This space-time variability of the reciprocal relations of the standards of space and time, or, perhaps, the recognition of the fact that “empty space” in its physical relation is neither homogeneous nor isotropic, compelling us to describe its state by ten functions (the gravitation potentials gμν)..."

See what I said above to Clinger. Spacetime isn't something that one can move through. A light beam doesn't curve because it moves through curved spacetime. It curves because it moves through inhomogeneous space.

If your model doesn't, then it is not obviously equivalent to GR. If you think it is equivalent, you need to prove that rather than merely assert it. Stop hand-waving and using flawed car analogies (see below) and convince us with some proper analysis.

Stop trying to assert that this is my model. I'm pointing out the original GR and what Einstein actually said and how its relevant to our understanding of black holes. The extract above is from his Leyden address where he talks of space as a form of gravitational aether. Have a look on arXivfor some recent papers on that theme.

It is unlikely to be an easy task, but until you do it there is no rational reason for anyone to believe that you are merely reinterpreting GR as opposed to, say, making grandiloquent noises to impress the gullible.

Geddoutofit. You're airily reinterpreting what Einstein actually said and you're dismissing patent scientific evidence. Come on, two parallel-mirror light clocks at different elevations don't stay synchronised:

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Now does the lower beam go slower or not? In your own time.

Your car analogy (why is it always cars?) says that you are still thinking in terms of something like a refractive index varying through space. It doesn't work, as we discussed before on the other thread.

It works. If you don't like the car analogy, too bad, because it's just a simplification of what Einstein said in 1916:

"In the second place our result shows that, according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity and to which we have already frequently referred, cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity of propagation of light varies with position. Now we might think that as a consequence of this, the special theory of relativity and with it the whole theory of relativity would be laid in the dust. But in reality this is not the case. We can only conclude that the special theory of relativity cannot claim an unlimited domain of validity; its results hold only so long as we are able to disregard the influences of gravitational fields on the phenomena (e.g. of light)."

Only he didn't say velocity. He said geschwindigkeit. Speed. You can see he's talking about speed because he refers to SR postulate, and refers to c elsewhere, and c isn't a vector quantity.

 

[Farsight]

...But what farsight is missing (in my opinion) is that this doesn't tell us anything about the the infalling observer measures. And considering that that is what's under discussion, it's odd that he glosses over it and keeps harping about the measurements of someone else.

I've said the infalling observer doesn't measure anything because light stops, and he stops too. The situation is similar to what an observer travelling at c would measure. I've said this repeatedly, it's pretty much the crux of this thread. A World Without Time: The Forgotten Legacy of Godel and Einstein is important when trying to appreciate this. You take time out of the equation by recognising that a clock displays an accumulated read-out of regular local motion, and when the clock stops it's the motion that's stopped, not time. If I put you in some gedanken box where I can slow down all motion, including the motion of electromagnetic propagation in your brain, you wouldn't notice. Then I can slow down the motion more and more until I've stopped it entirely, and you still wouldn't notice anything. You might think that "in your reference frame" you continue to make measurements, but you don't.

Of course, I'm no expert, but this is how I'm reading the thread, anyway. Hopefully I'll be corrected if I'm messing things up.

It's all pretty simple to understand. Sadly, the people who profess to be experts don't always seem too keen on people understanding things.

 

[Farsight]

.. I have indeed capitulated, in the sense of complete resignation that you are too far gone into crank-land...

Yeah yeah, you can't tackle the argument, so you sling abuse. Bye.

 

[W.D.Clinger]

Simplifying even more, have a read of Nasty little truth about spacetime physics

"Some of the most famous physicists in the world are not telling the truth about one of the most taken for granted concepts in scientific history. They are not telling us how they can come up with their fanciful time travel theories (wormholes, advanced and retarded waves traveling in spacetime, etc...) using a model of the universe that precludes the possibility of motion. Nothing can move in spacetime or in a time dimension-axis by definition. This is because motion in time is self-referential..."

Next.

Next?

You're quoting Louis Savain. Here's another sample of his crackpottery, from the same web site you quoted:

Abstract: Most people never think of the Bible as a source of scientific knowledge. In these pages, I argue that the Bible contains powerful secrets regarding the fundamental structure and composition of the physical universe. Once properly understood, these secrets will shake the foundations of physics and revolutionize the transportation and energy production industries. Our current internal combustion engines, vehicles and power plants will look painfully primitive compared to what is coming. We will kick ourselves in the rear for having been so wrong for so long. There is evidence to suggest that these secrets were known to one or more ancient civilizations. They were the builders of the megalithic structures at Baalbek (Lebanon), Tiahuanaco (Peru), and the Giza Plateau (Egypt). I will further argue that modern physics is either without foundation or based on erroneous and, at times, laughable concepts.

Another sample:

Part of my thesis is that the Bible not only reveals the existence of the lattice (i.e., the heavens, not to be confused with Heaven, the abode of God), but also describes the properties of its constituents (seraphim). It is important to understand that the lattice is what makes motion possible and thus, its creation must precede that of normal matter. Indeed, the very first verse of the book of Genesis says exactly that:

In the beginning, God created the heavens (lattice or energy field) and the earth (normal matter).​

Note the implied order of creation. This, of course, squarely contradicts the so-called big-bang theory of modern physics but that is another story for a future page.

There's more, lot's more. Instead of derailing this thread by discussing Louis Savain's crank physics, I think we should continue to talk about John Duffield's.

 

[Farsight]

The results of physical experiments are independent of coordinates, yes. But there are many physically different experiments one can do with light, clocks, and a black hole. GR predicts that some of those experiments will show clocks ticking slower near the horizon, and some will not. That's reflected in the fact that some coordinate systems have a coordinate singularity there, and some do not. (Those two statements are connected, because it's simple to describe experiments in coordinates in which most parts of the experiment are at rest.)

Come on sol, you know that gravitational time dilation is not symmetrical. All observers will agree that a clock near the event horizon is going slower than a clock in free space. You can muddy the waters by moving the observers and clocks, but we understand SR time dilation, and can account for it.

Let me add yet again that all of the above goes for perfectly flat spacetime. There is a horizon in flat spacetime (many actually, and your arguments apply just as well to the horizon of flat spacetime as they do to the horizons of black holes.

I think talking about say the Rindler Horizon would confuse matters. It isn't the same sort of thing as a black hole event horizon. A black hole is "out there", a Rindler horizon isn't.

Farsight insists on using one set of units that have the property that the tick marks on his rulers stretch out to infinity at a certain place (the horizon). As a result, he has trouble measuring, or even describing, anything that happens there, and he's fooled himself into thinking that this is somehow important.

I don't think I've mentioned rulers. I've talked repeatedly about clocks, and I'm not fooling myself about time, or about what a clock actually measures, or why a vertical beam doesn't escape a black hole. However that some of the people here have been fooled into thinking that you can make a stopped clock tick by adding a stopped observer, and then waiting forever.

 

[Farsight]

I don't read every post in this thread. When I do read something I disagree with, I usually comment. In this case, you're correct and RC is wrong. The existence of a black hole event horizon is a physical fact, and its existence doesn't depend on coordinate choice.

Thanks. I and others think more highly of people who say this sort of thing. Sometimes on a lively thread like this people won't pick up on errors "on their side", and I think it's the wrong thing to do. For example when we were talking to Johan, I wasn't going to sit on my hands when I thought he was wrong.

However: the existence of many other types of event horizons (Rindler, cosmological, de Sitter, Poincare, etc.) do depend on coordinate choice, and those horizons have exactly the same properties you are using to argue that the black hole horizon is a special place. Therefore, your arguments do not suffice.

Maybe I should say more then. I'll think about it. But I am reminded that I promised to get back to Johan on something, so I'll leave it at that for now.

 

[theprestige]

I think one of you will crack and say I think Farsight's got a point soon.

I can't speak for anyone else, but I promise that a distant observer, watching as I fall towards the event horizon of this thread, will never measure me saying "I think Farsight's got a good point."

 

[steenkh]

I can't steen, because the misunderstanding concerns time stopping. Only it isn't time that stops, it's light.

But I hear the other side saying that the light has not stopped, it only looks like this for an observer far away.

 

[steenkh]

Think of changing from (say) meters to feet - that's a simple coordinate change.

I was thinking more of the coordinates of the Earth where the North Pole is a strange place where North is not defined, but if we choose a coordinate system with North at a different place, the place where the North Pole was is not special at all any longer.

 

[ctamblyn]

Yes, it is simple. Two parallel-mirror light clocks at different elevations don't stay synchronised:

(...snip...)

Please don't feel the need to repeat your parallel mirror waffle. Standard physics already accounts for gravitational redshift without any trouble.

It's only complicated when one asserts that c and Z₀ are the same at both locations.

(...snip...)

They are fundamental constants (at least in GR). There is nothing complicated about it.

Please try to demonstrate rigourously, without resorting to analogies or hand-waving, that your theory - one in which either one or two scalar fields in 3D space account for gravity - is equivalent to GR.

You are going to fail, because even with two scalar fields you don't have enough degrees of freedom per 3D space point.

It's as simple as that^TM.

 

[ben m]

However that some of the people here have been fooled into thinking that you can make a stopped clock tick by adding a stopped observer, and then waiting forever.

And there it is again.

a) I think that time stops.
b) You did an error-free GR calculation in which time doesn't stop.
c) However, your calculation fails to take into account that time stops.
d) Therefore your calculation is wrong.
e) Yet another calculation that fails to contradict me!

I bow to a true expert troll. Well played, sir! Your years of practice have honed your trolling skills to the highest luster.

 

[ctamblyn]

When we then say we're using light clocks, and try to define a coordinate system with light that doesn't move, we can't. The guys whitewash over this by saying that's OK, you've got forever for this light to move, the stopped light and eternity cancel each other out. Only they don't. Nothing happens, that's it.

You don't yet understand what GR actually says.

We have two coordinate-independent facts about the spacetime around a nonrotating black hole:

1. Distant, stationary observers do not see objects fall through the horizon; they see them get rapidly dimmer and redder until, very soon, no more light is emitted. Those distant observers, in their peculiar, outwardly accelerating, non-inertial states, never see the infalling objects cross the horizon. To put it in an explicitly coordinate-free form, if an infalling object keeps emitting pulses of light at regular proper time intervals, only a finite number of those pulses will reach an asymptotic observer.

2. On the other hand, people free-falling into the black hole reach the event horizon in a finite time (as judged by the mechanical watches on their wrists, biological processes, muon decay clocks, strong decay processes, whatever). They go right through and, another finite amount of proper time later, hit the singularity. In coordinate free form: timelike geodesics, starting from outside the event horizon, can reach both the horizon and the singularity at finite values of their proper time parameters.

 

[ctamblyn]

I bow to a true expert troll. Well played, sir! Your years of practice have honed your trolling skills to the highest luster.

There are many threads spanning several years, a book (which reads like his threads) and a video interview. If he is trolling, he's putting far too much effort into it

 

[Reality Check]

Reality Check should have said there is no coordinate singularity at the event horizon in Kruskal-Szekeres coordinates. Adding those words in blue to his statements fixes them..

Thanks for the correction, W.D.Clinger.

I realized that I missed out this but it was too late to fix the original post. I would have posted a correction but Farsight has demonstrated that he has little knowledge of GR (e.g. is obsessing on one coordinate system) and no demonstrated ability to learn.

 

[Reality Check]

I've said the infalling observer doesn't measure anything because light stops, and he stops too. The situation is similar to what an observer travelling at c would measure.

And you continue to be wrong.
GR states that the infalling observer measures that his clock keeps on ticking as he passes through the event horizon.

That is what a guy called Albert Einstein (since you re really obsessed with arguments from authority) stated.

You even get SR wrong : An observer travelling at c would measure his clock ticking along as normal. That is what happens for an observer looking at their own clock at any speed. Just plug v=0 into the equations of SR.

 

[theprestige]

In thinking this over, I have a question, which I am hoping one of the other thread participants can answer for me:

If I am in the same frame as an observer falling through the event horizon, but my motion keeps me outside the event horizon for the duration of my observations, will I observe the horizon-crosser's clock to keep ticking at the same rate that she observes?

ETA: And is there a better way to formulate this question?

 

[ben m]

In thinking this over, I have a question, which I am hoping one of the other thread participants can answer for me:

If I am in the same frame as an observer falling through the event horizon, but my motion keeps me outside the event horizon for the duration of my observations, will I observe the horizon-crosser's clock to keep ticking at the same rate that she observes?

As you yourself are falling in towards the event horizon, you will always say that the event horizon is in front of you and receding away from you. If you started out with a partner a bit ahead of you, you'll see that partner approach (but never cross) the receding horizon, and (as with an outside observer) light from that partner will be seen as redshifted.

You have to be careful with the idea of falling in with an observer in the "same frame". Since there's a strong gravity gradient, an observer at a fixed distance from you cannot be in an inertial frame. Another observer in an inertial frame who starts out co-moving with you, will accelerate away from you.